Is a 45-day cycle normal?

What counts as a normal cycle

The menstrual cycle is counted from the first day of your period to the first day of the next one. It lasts 28 days on average, but that average hides a lot of variety: anywhere between 21 and 35 days is considered normal. Two women can have very different cycles and both be perfectly healthy.

Beyond 35 days, it is called a long cycle. At 45 days, you are clearly above the usual range.

One long cycle, or long cycles that keep coming back?

That is the first thing to ask yourself. A single 45-day cycle, in the middle of otherwise usual cycles, happens to many women: travel, intense stress, an illness, a change in daily rhythm can delay ovulation, and therefore your period. The body then catches up.

Long cycles that keep repeating tell a different story. They often mean ovulation happens late, or not at all some months. The most common causes are:

• the first years after your first period, while the cycle settles;
• stopping hormonal contraception, which can take several months to recover from;
• PMOS (formerly PCOS), which affects roughly one woman in ten and for which long cycles are a classic sign;
• perimenopause, in the years before menopause;
• a thyroid disorder, significant weight loss or gain, very intense sport;
• breastfeeding, in the months after giving birth.

What it changes for you day to day

A long cycle is not dangerous in itself. What it makes difficult is keeping track: classic apps announce your period for day 28, then show "late" for two weeks. You end up not logging anything.

If your cycles are long, log above all the first day of each period, even when it comes late. That information, over several cycles, is what lets your doctor understand what is going on, and lets an app built for this give you an honest window instead of a wrong date.

When to see someone

Book an appointment with your doctor, gynaecologist or midwife if:

• your cycles regularly go past 35 days, for more than three months;
• you go more than three months without a period, outside of pregnancy;
• your long cycles come with significant acne, increasing hair growth, unexplained weight gain;
• you are trying to conceive: long cycles make ovulation hard to spot, and early advice saves time.

Lovae is a wellbeing app, not a medical device. It helps you observe your cycle; it does not diagnose.

Sources

• Irregular periods (NHS)
• Qu'est-ce qu'une aménorrhée et quand faut-il s'inquiéter de l'absence de règles ? (Assurance Maladie, ameli.fr)
• Comprendre le syndrome des ovaires polykystiques : définition, causes et fréquence (Assurance Maladie, ameli.fr)

Pages consulted on 4 September 2026.